Might try downloading something like revo uninstaller then uninstall ACR reinstalling ACR then uninstalling ACR with revo uninstaller or some other uninstaller that gets all data and registry entries associated with the program it uninstalls, then reinstall. Pain but might work.
Edit: I have not used revo uninstaller in years but there used to be a setting in it that allowed removal of all associated files and registry entries but revo had to be installed and monitoring new installs for that to work, that is why I said uninstall ACR then reinstall ACR and then uninstall it with revo. Like I said have not used it in a while so may have changed but it used to be pretty good at explaining how to use it in the software.